Workaround for PowerVR clear issue.

src/gpu/GrDrawTarget.h

 /*
  * Copyright 2010 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrDrawTarget_DEFINED
 #define GrDrawTarget_DEFINED
 
@@ skipping 377 matching lines @@
                               int instanceCount,
                               int verticesPerInstance,
                               int indicesPerInstance,
                               const SkRect* devBounds = NULL);
 
     /**
      * Clear the passed in render target. Ignores the draw state and clip. Clears the whole thing if
      * rect is NULL, otherwise just the rect. If canIgnoreRect is set then the entire render target
      * can be optionally cleared.
      */
-    virtual void clear(const SkIRect* rect, GrColor color, bool canIgnoreRect,
-                       GrRenderTarget* renderTarget) = 0;
+    void clear(const SkIRect* rect, GrColor color, bool canIgnoreRect,
+               GrRenderTarget* renderTarget);
 
     /**
      * Discards the contents render target.
      **/
     virtual void discard(GrRenderTarget*) = 0;
 
     /**
      * Called at start and end of gpu trace marking
      * GR_CREATE_GPU_TRACE_MARKER(marker_str, target) will automatically call these at the start
      * and end of a code block respectively
@@ skipping 438 matching lines @@
                             const SkMatrix* localMatrix);
 
     virtual void onStencilPath(const GrPath*, GrPathRendering::FillType) = 0;
     virtual void onDrawPath(const GrPath*, GrPathRendering::FillType,
                             const GrDeviceCoordTexture* dstCopy) = 0;
     virtual void onDrawPaths(const GrPathRange*,
                              const uint32_t indices[], int count,
                              const float transforms[], PathTransformType,
                              GrPathRendering::FillType, const GrDeviceCoordTexture*) = 0;
 
+    virtual void onClear(const SkIRect* rect, GrColor color, bool canIgnoreRect,
+                         GrRenderTarget* renderTarget) = 0;
+
+
     virtual void didAddGpuTraceMarker() = 0;
     virtual void didRemoveGpuTraceMarker() = 0;
 
     // helpers for reserving vertex and index space.
     bool reserveVertexSpace(size_t vertexSize,
                             int vertexCount,
                             void** vertices);
     bool reserveIndexSpace(int indexCount, void** indices);
 
     // called by drawIndexed and drawNonIndexed. Use a negative indexCount to
@@ skipping 62 matching lines @@
 protected:
     GrClipMaskManager           fClipMaskManager;
 
 private:
     GrClipMaskManager* clipMaskManager() { return &fClipMaskManager; }
 
     typedef GrDrawTarget INHERITED;
 };
 
 #endif